Cyanine dyestuffs



Patented Mar. 3.0, 1948 2,438,782

UNITED STATES PATENT OFFICE CYANIN E DYESTUFFS John David Kendall, Ilford, England, asslgnor to Ilford Limited, Ilford, England, a British com- P y No Drawing. Application April 9, 1943, Serial No. 482,493. In Great Britain April 23, 1942 6 Claims. (01. 260-240) 1 2 This invention relates to the manufacture of of a strong base. Moreover, the di-nuclear dyedyestuffs and particularly to the manufacture of stuffs can be converted to tri-nuclear dyestuffs by dyestuffs which are capable of optically sensitisconverting them to quaternary salts by treatment ing silver halide photographic emulsions. with an alkyl or aralkyl salt and condensing them In application Serial No. 482,494, filed on even 5 with a molecular equivalent of a third reagent date herewith, there is described the production which may be the same as the second reagent;

of dyestuif intermediates of the general forby using a third reagent different from (though mula I: of the same class as) the second reagent unsymmetrical types of dyestuff are produced.

4 The types of dyestufi which can be formed ac- YTC=CHTOH= XR (I) cording to the present invention, by using an =0 alkyl or aralkyl quaternary salt of a heterocyclic =0 nitrogen compound of the thiazole, selenazole or 1 quinoline series containing a reactive methylene group (aCHzR5 group where R5 is a hydrogen where X and Y each represent an oxygen atom or 1 or a hydrocarbon $011?) in the or P a sulphur atom, R1 is a hydrogen atom or a, t1on to the quaternary nitrogen atom, ar therehydrocarbon group and R2 and R3 are hydro'carfore as follows:

Compounds of the general formula II:

bon groups.

According to the present invention, dyestufis are produced by condensing a dyestuff interme- Y O.=CH CH=IJ CZ(E (OH=CH)r41 (H) diate of general formula I with an alkyl or aralkyl quaternary salt of a heterocyclic nitrogen 4 compound of the thiazole, selenazole or quinoline N. series having, in the a or 7 position to the quaterl l nary nitrogen atom, an external reactive methylene group (which includes an external methyl Compounds of the general formula III:

R3 R5 --D1---- r D, I Y-c=cH-cH=c-0=b(011=cl1)"-11 (In) 1 I= cH-cH ,.=cc=o B4 A III- =0 R1 group or mono-substituted methyl group). In general formulae II and III the symbol R4 It is a remarkable property of the dyestuff represents an alkyl or aralkyl group, A repreintermediates of general formula I that not only sents an acid radicle, D1 and D2 represent the is the --XR2' group reactive but the :5 group is residues of nuclei of the thiazole, selenazole or also reactive. In many cases, therefore, the conquinoline series, and n is nought or 1.

densation proceeds directly between one molecu- Compounds of general formula II may be conlar equivalent of the compound of general forverted to compounds of general formula III by mula I and two molecular equivalents of the secreacting the former compounds with an alkyl or 0nd reagent to form a dyestufi which contains aralkyl salt (RsA) which converts the thio group three heterocyclic nuclei. It is found that the (=8) to a thio ether group SRs, thus: tri-nuclear dyes are generally formed, if suitable I quantities of the reagents are used, where the reaction is effected merely by heating the reagents together or where the reaction is efiected in the presence of at most only a small quantity of a Q base, though where the second reagent is a quino- R1 R1 A line type of compound di-nuclear dyestuffs are frequently formed and reacting the resulting quaternary salt with In all cases di-nuclear dyes can be produced by a further molecular equivalent of an alkyl or using molecular equivalents of the reagents and aralkyl quaternary salt of a heterocyclic nitrogen effecting the reaction in the presence of excess compound of the thiazole, selenazole or quinoline series. The two stages in the process can be effected simultaneously in one stage if desired.

Heterocyclic nitrogen compounds which may be employed as quaternary salts may be, for example, the appropriately substituted thiazoles, selenazoles and their polycyclic homologues such as those of the benzene, naphthalene, acenaphthene and anthracene series, thiazolines and selenazolines quinoline and c and B naphthaquinolines and lepidines. The polycyclic compounds of these series may also be substituted in the carbocyclic rings with one or more groups such as alkyl, aryl, amino, hydroXy, alkoxy and methylene-dioxy groups or by halogen atoms. All "of such compounds must, of course, contain the specified reactive methylene group. V

As indicated above, the groups R1, R2,'R3 and R may be hydrocarbon groups and this is to be understood to include alkyl, aryl and aralkyl groups and unsaturated hydrocarbon groups e. g. methyl, ethyl, propyl and higher alkyl groups, benzyl and naphthyl-methyl groups,'phenyl and naphthyl groups, and allyl and cinnamyl groups. Such hydrocarbon groups may contain substituent groups, e. g., amino, hydroxy and alkoxy groups or may contain substituent halogen atoms. The groups R4 and Re referred to in the foregoing formulae are alkyl or aralkyl groups and may be any of such groups mentioned above The group R4 is preferably an alkyl or hydroxyalkyl group. 5 I

Thegroup A is an acid radicle and examples are halide groups, alkyl sulphate, p-toluene sulphonate, and perchlorate groups. t 7 The following examples illustrate the inven- -tion but are not to be regarded as limitingit in any way:

Example 1 Preparation of the dyestufl of the formula:

(J2EE O 2H5 thio-crotonylidene) tetrahydrothiazole and 1.02

gms. of l-methyl benzthiazole ethiodide. were keto-5- (y-ethoxy-crotonylidene) tetrahydrothiazole, 1.02 gms. of l-methyl benzthiazole ethiodide, 20 cos. of ethyl alcohol and 0.46 cc. of triethylamine.

Example ,2 Preparation of the dyestuff of the formula:

(13H: 7 SO=CHOH=COH= N-OrHb S:

l?I-C=O CzHs gms. of lepidine ethiodide were dissolved in 40 cos. of methyl alcohol and 1.02 ccs. of diethylamine were added. The solution was gently warmed and then allowed to cool. The desired dyestufi separated out and after washing with Water, methyl alcohol and ether, had a melting point of 179 C.

0.88 gm. of 2-thio-3-ethyl-4-keto-5-(y-ethylthlocrotonylidene) tetrahydrothiazole, and 2.08 gms. of p-toluquinaldine 'ethiodide were dissolved in' cos. of ethyl alcohol by gentle warming and 1.02 cos. of diethylamine were added. Theresulting solution was warmed'for 2-3 minutes and then allowed to cool. Thadesireddyestuff separated and after washing with ethyl alcohol, wa-

ter and ether, was obtained'as crystalsz'r'nelting at 207 C.

Example 4 Preparation of the dyestufi of theformula:

CH3 7 x V r 2.1 gms. of 2-thio 3 methyl-4 -1 eto-5 (##ethyl- ,thio-crotonylidenel-tetrahydrothiazole; and 2.4

' gms. of "l-methyl benzthiazole ethiodi'de were dissolved in 40 ccs.ethylalcoholiby gentle warmand after washing was obtained as crystals melting at 255C. It gave a purple-blue solution in methyl alcohol.

In thisex'ample a dinuclear dyestufl is obtained asa result ofthe use of a large excess of diethylamine. V Example 5 Preparation of the dyestuif oi the formula:

. thio crotonylidene tetrahydro-oxazole [and 1.02

girls. of lmethyl b'enztl'iiazole" ethiodide' were dissolved in 20. cos. ofe'thyl" alcohol by gentle thio-crotonylidene)-tetrahydro-thiazo1e and 3 1 warming, and0.46 cc. of 'itriethylam'ine j were added. iTh e resulting" solution was heated ona water bath for 15 'minutes'and th'en*coole'd. The desired 'dyestuff crystallised out and :after washing withwater, ethyl alcoholand ether-was obtained. as crystals melting at 218. 'C. decomposition.

2,418,817. 2 .5 Example comprlsescondensing a dyestufl intermediate of v the general formula: Preparation of the dyestufl of the formula:

. where X and Y are each selected from the class N consisting of oxygen atoms and sulphur atoms. R1 is selected from the class consisting of the 02H: 1 1 hydrogen atom and hydrocarbon groups, and R2 V. v and R3 are each hydrocarbon groups, with a sec- 0.54 gm. of 2-thio-3-methyl-4-keto-5-(y-ethylond reagent which is a compound selected from 'y-ethylthio-allylidene) -tetrahydro-thiazole, 1.52 the class consisting. of alkyl and aralkyl quatergms. of l-methylebenzthiazole ethiodide and 1 nary salts of heterocyclic nitrogen compounds of cos. of ethyl alcohol were warmed together and the thiazole, selenazole and quinoline series hav- 0.2 cc. of diethylamine was added. A green-blue ing in one of the a and 7 positions to the heterocolour appeared almost immediately and heating cyclic nitrogen atom a substituent reactive methwas continued for 10 minutes. The blue soluylene group,

tion was then cooled and the precipitated dye 2. Process according to claim 1 wherein the washed with ethyl alcohol, hot water, hot benreagents are used in the proportion of one molecuzene ethyl alcohol and ether. It crystallised from lar equivalent of the said dyes'tufi intermediate to methyl alcohol as green crystals. Melting point at least two molecular proportions of the said sec- 180" C. 0nd reagent, and the reaction is effected in the Example 7 2 gggience of at most only a small quantity of a Preparation of the dyestufl of the formula: 3. Process according to claim 1 wherein the reagents are used in substantially equimolecular B proportions and the reaction is effected in the presence of a strong base in a quantity in excess SC=OHCH=C-CH=C of that necessary to react with any acid by-prod- =g nets of the reaction.

N 0=o 4. Dyestuffs of the general formula: 2H6 RI B |----D1--| H 85 Y-o=cn-on= E=o(crr=ci1).-i r The preparation was effected as in Example 4 using '7 gms. of 2-thio-3-ethyl-4-keto-5-(-y-ethylthio crotonylidene) tetrahydrothiazole, 12.32

gms. of l-methyl benzthiazole ethiodide, 11.1 cos. 40 1 of diethylamine and 140 cos. of ethyl alcohol. The where R1 and R5 are each selected from the class dye was boiled out with methyl alcohol and thus consisting of the hydrogen atom and hydrocarbon obtained as crystals, M. P. 185 C. groups, R3 is a hydrocarbon radicle, R4 is selected As already indicated, the dyestufis of this infrom the class consisting of alkyl and aralkyl vention are optical sensitisers for silver halide groups, Y is selected from the class consisting of photographic emulsions. Thus, the dyestuflfs of oxygen atoms and sulphur atoms, n is selected the foregoing specific examples when incorpofrom the class consisting of nought and one, and

rated in gelatino-silver iodo-bromide emulsions D1 is a residue selected from the class consisting impart to such emulsions sensitivity in the red of thiazole, selenazole and quinoline residues. and far-red regions of the spectrum. 5. Dyestuffs of the general formula:

Thus the sensitising maxima of the dyestufis where R1 and-R5 are each selected from the class of the foregoing examples in a gelatino-silver consisting of the hydrogen atom and hydrocarbon iodobromide emulsion are as follows: groups, R3 is a hydrocarbon radicle, R4 is selected from the class consisting of alkyl and aralkyl groups, Y is selected from the class consisting of oxygen atoms and sulphur atoms, n is selected from the class consisting of nought and one, and D1 and D2 are each residues selected from the class consisting of thiazole, selenazole and quinc- Example 1: Sensitising maximum at 7600 A. Example 2: Sensitising maximum at'7600 A. Example 3: Sensitising maximum at 7300 A, Example 4: Sensitising maximum at 7100 A, Example 5: Sensitising maximum at '7200 A.

What I claim is: line residues. 1. Process for the production of dyestuffs which 6. yestufis oi the n l for la! a I Di'-- -Di-- R. Y-c=cH-oH=oc=b-(oH=0H ..-1i1 i I= cH-cri 'J-=c R4 where R1" and R5 are eaohselected from the clas's consisting of the hydrogen atom and hydrocanbon groups, Ra is:a, hydrocaitbon radicle, R4 is selected from the class consisting of alkyiend aralkyl groups, Y is selected from the class consisting of oxygen atoms and sulphur atoms, 12 is selected from the class consisting of nought and. one, and

D1 and D2 are diiferent residuesselectedfrom the Thefollowing references are of .record. in the file of thisspatent:

Number Number 8 UNITED STATESJATENTS Nair nee Date, Brooker Apr. 27; 1937 Zeb Oct. 4, 1938 Brooker Aug. 29, 1939 Brooker-x Oct. 24;.1939 Brooker Oct524, 1939 Sprague Nov 18', 1941 FOREIGN PATENTS Country 7 Date; France 1936 (Additionitofl93fi22)s. t GreatsiBritain1;-;;;e e e 1939* switzerlandun nnn Apr; 1942" 

